1. Field of the Invention
This invention relates to a sheet of porous resinous material.
2. Description of the Prior Art
Porous resinous material, such as porous polytetrafluoroethylene, is usually employed in various kinds of electrical apparatus because of its excellent properties, including a low dielectric constant. There are, however, limitations to the dielectric constant and other properties of the porous resinous material known in the art, and therefore, to the scope of it applications.